1. Field of the Invention
The present invention relates, in general, to methods and systems for animated lighting, and, more particularly, to systems, devices and methods for simulating a flickering flame providing kinetic light movement.
2. Relevant Background
A difficult challenge for a special effects artist is the simulation of a single candle flame. Simulated flames in large fires such as fireplaces or stage sets are comparatively easy to design because they are normally viewed from a distance, and much of the effect of a large fire involves glow and embers, which can be readily simulated. A single candle, however, is often viewed at short distances with the focus of the effect falling on the flickering light of the solitary flame moving kinetically or randomly on a wick.
Flames are the visible, light-emitting part of a fire. Solitary flames are complex kinetic interactions of fuel, temperature gradients, convection, and ambient airflow. These interactions produce a continuously and randomly moving light having loosely defined regions of various colors where the regions change size and shape kinetically or in unpredictable manners in space. Despite the complexity, people are so familiar with the appearance of natural flames that it is very difficult to provide a convincing simulation that appears real or natural to a viewer, especially at short viewing distances of several feet or less.
Combustion-based candles create safety issues in many environments because of the presence of flame and heat. These conventional candles are high-maintenance and so are not suitable for long-term usage such as in religious buildings, theme parks, memorials, window displays, museums and the like without continuous maintenance. On the other hand, conventional wax candles produce a light that appeals to many people and can be readily manufactured for a wide variety of applications such as table lighting, room lighting, wall sconces, spiritual ceremonies, theatrical lighting, decorative lighting, and lighting for holidays and special events. Hence, a continuing need exists for an artificial flame simulator that can be used more safely and with less maintenance than conventional wax or combustion candles, and the artificial flame simulator or device should produce a pleasing and realistic simulation of solitary flames and be adaptable to a variety of form factors.
There are a variety of flame imitation novelty products that utilize various methods to simulate a real flame for display purposes such as those disclosed in U.S. Pat. Nos. 7,125,142, 6,454,425 and 4,550,363. Specifically, U.S. Pat. No. 7,125,142 describes a device that uses multiple colored lights affixed to a translucent shell where the lights are energized according to a computer program that attempts to animate the light without moving parts. U.S. Pat. No. 6,454,425 discloses a candle flame simulating device that includes a blowing device for generating an air flow and for directing the flowing air toward a flame-like flexible member, in order to blow and oscillate or to vibrate the flame-like flexible member so as to simulate a candle. U.S. Pat. No. 4,550,363 discloses an electric-light bulb fitted with a light permeable and light-scattering lamp casing. These and other attempts result in flame displays that are relatively poor imitations of a real flame and have not been widely adopted by the commercial or retail markets. In addition, such devices typically require substantial energy inputs and require frequent battery replacement, which can drive up purchase and operating costs and require undesirable levels of maintenance for ongoing use.